The assembly of paddle-wheel Ru2 building units affords a new trimetallic carbonate, Cs3Cd(H2O)6[{Cd(H2O)3}2{Ru2(CO3)4}3]·10H2O (1), that contains structurally near-perfect kagome layers, {Ru2(CO3)4}n3n-, linked by octahedral Cd(H2O)32+ into a nanoscale kagome network exhibiting ferromagnetic ordering below 3.5 K. The investigation of influences of the grinding method on the crystal samples of compound 1 reveals that the coercivity increases from ∼2.5 Oe to 44.0 Oe upon a grinding treatment for 180 minutes. The results demonstrate that compound 1 can vary from a soft magnet to a hard magnet simply by manually grinding the crystal samples to the nanoscale.